1. Field of the Invention
The present invention relates to an apparatus and method for directly measuring cooling air pressure and the temperature of an integrated circuit.
2. Description of the Prior Art
Measurement of integrated circuit board temperatures is critical for continuous operation without overheating and damaging the circuits. Integrated circuits may develop a build up of heat at various points in the circuit. If the temperature is too high at any point, the circuit may be damaged. Therefore circuits often use air or fluid cooling systems to prevent overheating. To ensure that the cooling system is working properly and that the circuit will not be damaged, the temperature of the circuit is monitored.
Heretofore, with air cooling, circuit temperatures have been measured indirectly utilizing sensors measuring the air temperature around potential "hot spots" in the circuit rather than directly measuring the circuit temperature. The temperature of the integrated circuit must then be extrapolated from the sensed air temperature. However, this technique is not entirely satisfactory as a number of variables can affect the air temperature so that the reading may not reflect the true temperature of the integrated circuit. The problem of accuracy is especially difficult when the integrated circuit uses air cooling. Differences in flow and temperature variations in other components may have a significant influence on the air temperature while the temperature of the integrated circuit may vary only slightly.
Sensors have also been imbedded in the circuit board next to the circuit. As with sensing air temperature, this method is indirect and requires extrapolation to give an estimated circuit temperature. Devices for measuring temperature and pressure have heretofore required an added separate circuit to drive the temperature sensor so that extra circuitry is needed along with an additional power source.
It can be seen then that a temperature monitoring system is needed which directly measures temperature of an integrated circuit and which is driven from existing voltage in the integrated circuit.